The present invention relates in general to a sintering method for a carbon nanotube of a field-emission display, and more particularly, to a method using a locking member to interlock the cathode structure with the anode structure an electric connector based. A specific electric field is applied during the vacuum sintering process. The carbon nanotube of the cathode structure is inclined to the anode by a smaller angle or parallel with the electric field. One end of the carbon nanotube is attached to the cathode and perpendicular thereto.
The conventional cathode structure of field-emission display, such as the Spindt type metal spike configuration is fabricated by thin-film lithography process. The threshold electric field of this type of field-emission display is as high as hundreds of Volts per micron. Therefore, the cost for the driving device is relatively high.
The carbon nanotube structure has very good aspect ratio. The gauge of the carbon nanotube is normally several to tens of nanometers, and the length of the carbon nanotube can reach several microns. The carbon nanotube is also thermally stable and stretchable, such that it has been considered to be a very good electron emission source of field-emission displays. For example, the carbon nanotuble directly grown on the cathode electrode by CVD has been developed and readily applied already. Such technique uses catalytic metal to vertically deposit the carbon nanotube on the cathode electrode, followed by patterning process to form uniform carbon nanotube allowing the current density of tens to hundreds of mA per square cm. However, such technique, being limited by the material and structure factors, provides a threshold electric field as high as 10V/μm. It can thus be formed on silicon wafer currently and is hardly commercialized.
Another conventional nano-technology includes arc discharge. The arc discharge can produce a carbon nanotube more suitable for use in the field-emission display. Such technology combined with screen printing and coating reduces the threshold voltage under 2V/μm. The carbon nanotube formed on the cathode electrode surface is patterned to form the electron emission source. However, the thick film of the carbon nanotube formed on coating technique results in nondirective carbon nanotube, so as to produce terminal disorder of the electrons. Therefore, the density of the electron emission is non-uniform, and the electrons generated at a higher terminal easily generate shielding effect upon the neighboring terminals, such that the electron generation in the neighboring terminals is affected. In addition, the property of the adhesion material typically used to attach the carbon nanotube to the cathode electrode affect the dispersion and distribution of the carbon nanotube.
Currently, the vacuum sintering technique allows the carbon nanotube directly attached to the cathode electrode, such that the drawbacks caused by the coating process and the adhesion material are resolved. Therefore, the density of the carbon nanotube can be increased to increase the density of electron generation. However, as the carbon nanotube is randomly applied to the glass substrate of the cathode structure, interference and interleaving effect between the carbon nanotubes occur. One end of the carbon nanotube cannot be vertically attached to the glass substrate by the application of electric field.